Dictionary A B C D E F G H I J K L M N O P Q R S T U V W X Y Z palindrome Words, numbers and phrases that can be read the same backwords as forwards. Some examples include: "mom", "racecar", "34543", or the phrase "never odd or even". paradox A statement that appears to contradict itself, for example, suggesting a solution which is actually impossible (cfTortoise and Hare Race). parallel Lines that are in the same plane that do not intersect (cfRectangles Discussion). parallelogram A quadrilateral that contains two pairs of parallel sides (cfParallelograms Discussion, Rectangle Discussion). pattern Characteristic(s) observed in one item that may be repeated in similar or identical manners in other items. percent A ratio that compares a number to one hundred. The symbol for percent is % (cf Percents Discussion). perimeter The sum of the lengths of all the sides of a polygon. (cfLength, Area, and Perimeter Lesson). permutation A a particular ordering of a set of objects. For example, given the set {1, 2, 3}, there are six permutations: {1, 2, 3}, {1, 3, 2}, {2, 1, 3}, {2, 3, 1}, {3, 1, 2}, and {3, 2, 1}. personal view An approach taken by mathematicians and philosophers to calculate probability. Using their knowledge and reasoning skills, they think through the problem. See theories of probability (cf Probability vs. Statistics Discussion). Pi The designated name for the ratio of the circumference of a circle to its diameter. pie graph A diagram showing a system of connections or interrelations between two or more things by using a circle divided into segments that look like pieces of pie. polygon A closed plane figure formed by three or more line segments (cf What Are Tessellations Discussion). polyhedra Any solid figure having many faces (cf Polyhedra Discussion). prime number A number that has exactly two factors, 1 and the number itself (cf Venn Diagrams Discussion). prisoners values for c in the Julia Set or Mandelbrot set where at each iteration the resulting value becomes smaller and smaller, approaching zero (cf Prisoners and Escapees -- Julia Sets Discussion). probability The measure of how likely it is for an event to occur. The probability of an event is always a number between zero and 100%. The meaning (interpretation) of probability is the subject of theories of probability. However, any rule for assigning probabilities to events has to satisfy the axioms of probability. protractor An instrument for laying down and measuring angles on paper, used in drawing and plotting (cf From Geometry to Probability Discussion). Pythagorean theorem A theorem in geometry that states given a right triangle, the sum of the squares of the lengths of the legs is equal to the square of the length of the hypotenuse. This is often represented by the equation a2 + b2 = c2, where a and b are the length of the legs and c is the length of the hypotenuse. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Please direct questions and comments about this project to Addison-Wesley math@aw.com © Copyright 1997-2001 The Shodor Education Foundation, Inc. © Copyright 2001 Addison-Wesley. All rights reserved.